Fluoroboric alkylation of thiophene



Patented Oct. 31, 1950 rLUoRoBonic ALKYLATION F THIOPHENE Philip D.Caesar, .Wenonah, George C. Johnson, Woodbury, and John W. Brooks,Wenonah, N. 3., assignors to Socony-Vacuum Oil Company, Incorporated, a.corporation of New York No Drawing". Application June 1, 1946, SerialNo. 673,900

Claims. 1

The present invention relates to the synthesis of homologues ofthiophene and, more particularly, to a process for alkylating thiopheneand alkylthiophenes in the presence of catalysts of the typedihydroxyfluoboric acid and the products of the reaction of water andboron trifiuoride in which the amount of water is carefullycontrolled.

Alkylation reactions in general are well known in the art and areusually considered to be those reactions in which the union betweenalkyl radicals and molecules of alkylatable organic compounds occurunder conditions of temperature, pressure and time usually referred toin the art as alkylating conditions. The compounds produced by the unionbetween the alkyl radicals and the alkylatable organic compounds arecalled alkymers and represent, structurally, the addition of theoriginal alkyl radical to the organic compound molecule. The totalproduct of an alkylation reaction is referred to in the art as analkylate which usually contains the alkymer, residual amounts ofreactants and products produced by secondary reactions that occurconcurrently with the principal or alkylation reaction.

Generally speaking, the temperature and, usually at least to a certainextent, the pressure and the time of reaction employed in alkylationoperations depend upon whether the alkylation is efiected in the absenceor presence of alkylation catalysts. Alkylations carried out in theabsence of a catalyst are generally referred to as thermal alkylationwhile those in which a catalyst is employed are known as catalyticalkylations.

In alkylation reactions, the alkyl radical is supplied by a compoundknown to the art. ascapable under reaction conditions of supplying analkyl radical and, accordingly, such compounds are known as alkylatingagents or alkylants; Compounds within this classification are olefinicfhydrocarbons, alkyl halides, alcohols, aral kyl hal ides, organic andinorganic esters, ethers, alkyl sulfates, alkene oxides, thioethers andmercaptans. d

It is well known to'those'familiar'with the art that the synthesis ofthe homologues of'thiophene has been effected mostly-through the Fit thecommercial utilization of this synthesis.

Furthermore, the reaction time varies for the production of differenthomologues. For example, the production of 2,3 thioXen 2,3-uimethy1-thiophene) from 2-iodo-3-methylthiophene (2- iodo'-3 thiotolen) requiresseveral days and the production of 2,5-thioxen (2,5-dirnethylthiophene)from 5-iodo-2 thiotolen (5-iodo-2-methylthiophene) required an inductionperiod of four weeks and then was completed in a few hours. TheFriedel-Crafts synthesis has also been proposed for preparing thiophenehomologues by the condensation of thiophene and halogen alkyls in thepresence of aluminum chloride as a catalyst. Although this catalyst hasbeen used with considerable success in the alkylation of aromatichydrocarbons, its use has met with only moderate success Where thiopheneis concerned. This appears to be due to the relative instability of thethiophene ring.

The alkylation of thiophene has been an exceedingly difficult reactionto carry out with good yields of the desired product. The usualalkylation catalysts such as aluminum halides, and hydrogen fluoridecause excessive resinification of the thiophene. The resinificationusually occurs before alkylation can be effected and, if the expectedreaction product is formed, it is only formed in very small amounts.

It has now been discovered that homologues of thiophene can be producedemploying a series of liquid catalysts containing boron and fluorineranging from relatively pure dihydroxyfluoboric acid throughdihydroxyfiuoboric acid at least partially saturated with borontrifiuoride and mixtures of dihydroxyfluoboric acid and hydrogenfiuoride to aqueous solutions of boron trifluoride containing carefullycontrolled amounts of water equivalent to up to and including 6 moles ofwater per mole of boron trifluoride. This catalyst series may be definedas the boronfluorine acids containing about 5 to about 17 per cent ofboron, at least about 30 per cent and not more than about per cent offluorine, not more than about 53 per cent of oxygen and not more thanabout '7 per cent of hydrogen. However, it is preferred to'use the groupof catalysts within the foregoing class which has as its members thoseboron-fluorine acids containing about 10 to about 15 per cent of boron,at least about 45 per cent and not more than about 80 per cent offluorine, not more than about 39 per cent of oxygen and less than about4 per cent of hydrogen. In order that those skilledin the art may have abetter understanding of the classification of the novel catalysts, abrief review of the methods of preparation and the products producedwill boron trifluoride and boric acid :in accordance or from hydrogenfluoride and boric anhydride in accordance with the following equation:-

For the purposes of this invention-ithe-total re-' action product ofeither reaction may be used or the dihydroxyfluoboric acidlI-IgBOzFz)may beta isolated in a relatively pure stateby anysuitable.

means, as for example, by distillation at reduced-i pressure. Thealkylation of thiophene is also catalyzed by the reaction productobtained by saturating dihydroxyfiuoboric acid with boron trifluoride toobtain-1a boron-trifiuoride complex? This reaction may be representedOfC"H3BO2F2. byrth'e following equation:

The reaction product produced by saturating water at temperatures-notgreater than' about 70 15080 'degreesFahrenheit and represented by theequation:

(about 19 to about..-21percent-water by weight).

also maybe used-as a catalyst .inthe formationof homologues ofthiophene..- Other aqueoussolue tions of boron trifluoridecontaining. acontrolled. amount of water equivalent to...1.to 6 :moles .of. waterapermole of borontrifiuoride likewise catalyzeethese reactions. Avcatalyst-allied to. these boron trifluoride hydrateslboron triiluoridecone. taining-lto .6 molesof water per mole of BF3) is; thatobtainedbyadding boron trifluoride to-a42.

acidand byrea'cting boron trifluoride," water and boric acid in theproportionsrof' boron trifluoride' 4':moles,' boric acid "ljmoleeandwater "3 moles.

In UISrPaItent No. 21348;,637 Meinert'has shown that" the saturation "ofwater with "BF: probably produces 'flu'o'boric acid" and certainhydratesof' bororr trifiuoride? However, the' composition ofthe'rea'ction product is only speculative.

hereinafter and discussed in that tabulation:

CATALYST A no can Iirview of 'the foregoing, the novel catalysts aretabulated conjunction with 4 The theoretical compositions of thesecatalysts are given in the following tabulation:

Catalyst Boron Fluorine 5 Hydrogen. Oxygen The foregoing catalysts canbe divided into at least three groups on the basis of their acceleratingeffect upon the alkylation of thiophene. However, the preferredcatalysts are catalysts B,"C,.D,' E,J,"L and M. Catalysts BEJ, L, E andD are the most effective, catalysts C, Mand Hare slightly lesseffective, and catalysts A, K, F-and For example, thiophene can G stillless effective. be. alkylated using as an alkylating agent the activeolefins isobutylene, di-isobutylene and octene-l and the catalyst B.However, it is to be notedthat under the same conditions with whichthiophene was alkylated with isobutylene using catalyst B there was noreaction between benzene and isobutylene; It will be observed thatcatalyst B contains about 54% fluorine and that the weaker catalysts; i.e., A, G, K; F, C and H all contain less than 54% fluorine. Accordingly,the

preferred catalysts consist essentially of boron fluorineacidscontaining not more than 54%- fluorine, up to 17% boron'and atleast 2.8% hydrogen and h'avinga fluorine to oxygen ratio of about 0.65to' about 1.78 to 1. Within the foregoing. class of catalysts is asmaller groupconsisting essentiallyof boron-fluorine acids containingabout 34 to 44% fluorine, about 5 to about 8% boron, about 5 to about 7%hydrogen and having a fluorine to oxygen ratio of about 0.65 to about 1to 1. Especially preferred is a catalyst consisting, essentially of aboron-fluorine acid containing about 45.3% boron,. aboot 3.6%hydrogenand about 38.2% oxygen.

Catalyst D. catalyzes/the alkylaticn of thicphene using. octene-l andpropylene as the alkylatingagent. Catalyst C is effective in thealkylation of thiophene with octene- 1 and propylene as the alkylatingagents. Catalyst E is effective. in. the. alkylation of thiophene withoctene-l and-hexadecene-L. Catalysts .-F.and G catalyze the alk-ylation..of .thiophene with isobutylene... Thiophene. is alkylated.withpentene-1,..octene-.-1 .and isobutylene. in the presence of.catalystsH andJ. CatalystsK and. Lcanbelysts vary. widelyintheiractivity for this .alkylation. For example, catalyst E catalyzesvthealkylation: of thiophene with olefins ranging from propylene tonormal olefins of :16 carbon atoms:

or more, say 26 'carbonatoms; whereas catalyst G can be used only withsuch'active' olefins' as iso-- butylene and isoamylener On the'otherhand,

catalyst 13 canbe used to catalyze the alkylatioii' ofethiophene using 1alkyl halides and alcohols as the-*alkylating'agents. On the basis ofthe fore:

going andmtherexperimental data, the catalysts. enumerated?hereinbefore.can be i-rated with re-' fluorine, about 12.9

spect to effectiveness "indicated in the followrade at autogenous or.higher pressures. Al-

tng table: though, in general, temperatures within the Catalyst Desig-Per Cent 32,922}: Per Oent Per Cent Per Cent Set nation F Ratio B HEfiectiveness Most effective.

++ Slightly less eflective.

+ Still less eiiective,

It will be noted that the most efiective catalysts are those havingfluorine concentration in excess of 50 per cent and a fluorine tooxygenratio of at least about 1.8:1. These catalysts may be used withsubstantially all alkylating agents; i. e., active olfins such asisobutylene and isoamylene as Well as the relatively inactive normalolefins of three to 26 carbon atoms. These catalysts may also be used inalkylating alkylatable thiophene when using such alkylating agents asalkyl halides and alcohols. Catalysts containing in excess of about 45per cent fluorine and having a fluorine to oxygen ratio of about 1.2 toabout 1.8:1 are not effective with such olefins as the normal olefinshaving three to 26 carbon atoms in the molecule or other alkylatingagents such as the alkyl halides and alcohols, but are effective withactive olefins such as isobutylene and normal olefins of five to eightcarbon atoms. Catalysts containing between about 34 and about 44 percent fluorine and having a fluorine to oxygen ratio of about 0.65 toabout 1.0:1 are efiective catalysts for the alkylation of alkylatablethiophenes when using such active alkylating agents as isobutylene andisoamylene.

Accordingly, it is an object of the present invention to provide a meansof producing homologues of thiophene Iby alkylation of thiophene withalkylating agents under alkylating conditions in the presence ofalkylating catalysts defined as compounds of boron and fluorinecontaining about 5 to about 17 per cent of boron, at least about 30 percent and not more than about 80 per cent of fluorine, not'more thanabout 53 per cent of oxygen and not more than about? per cent ofhydrogen. It is another object of the present invention to provide amethod for the production of homologues of thiophene by the alkylationof thiophene with olefins in the presence of catalysts containing aboutto about per cent of boron, at least about 45per cent and not more thanabout 80 per cent of fluorine, not more than about 39 per cent of oxygenand less than about 4 per cent of hydrogen. It is a further object ofthe present invention to provide a method for catalytically alkylatingthiophene with alkylating agents under alkylating conditions oftemperature, pressure'and reaction time in the presence ofdihydroxyfluoboric acid. Other objects and advantages will becomeapparent from the following description.

In general, the formation of homologues of thiophene by alkylation usingknown alkylating agents and the catalysts defined herein takes placeunder alkylating conditions of temperature, pressure and reaction time.The temperature may be from about 10 to about-200 degrees centi-'(catalysts B, C, D, E, J, L and M), temperatures in the lower part ofthe range are preferred. On the other hand, whenusing a less activecatalyst (catalysts A, F, G, Hand K) temperatures in the upper portionof the range may be used. The time of reaction may be from about 15minutes to about 3 hours or longer, dependent upon the alkylating agentand the particular catalyst. Illustrative of the foregoing are thefollowing non-limiting examples.

EXAMPLE I Catalyst preparation (E) Borie anhydride, about 696 parts byweight (about 10 moles); about 1,000 parts by weight of petroleum etherwere placed in an autoclave and about 900 parts by weight hydrogenfluoride (about 45 moles) were added at about 20 degrees centigrade. Thereaction mixture was stirred under autogenous pressure for about minutesand about 1640 parts by weight of catalyst recovered. This catalyst isdesignated catalyst B.

Alkylation During the course of about one hour about 25 parts by weightof isobutylene (about 0.45 mole) were added to about 42 parts by weightof thiophene (about 0.5 mole) and about 0.025 part by weight (based onthe Weight of the reactants) of catalyst B.. The reaction mixture wasstirred and maintained at about 40 to about 45 degrees centigrade duringthe addition of the alkylating agent. Sixty-seven parts by weightofproduct were recovered. The product was separated from the catalyst,water-washed and distilled in a modified Vigreaux flask. The followingcuts were taken:

and. abUu t84 1partSibyiweightiof.irT-dsobutylene(aboutzozfiimole-rswere added. f The reactionfmix=- ture was heated withstirring to about 80 degrees centigrade for about one hour. Thereafterthe product was separated from the catalyst and water-washed. Thewater-washed product was" distilled and the following cuts taken:

- iii" Alkyl tiomaw About one mole of thiophene (about weight) ofoctene-l and about 80 partsby weight of catalyst D prepared as describedhereinbefore were stirred in an" autoclave for about 2 hours at about 70degrees centigrade.

uct was-separated from the catalyst, water Product Boiling Parts ywashed and distilled in a modified Vigreaux flask? Range welglglt Thefol g cuts were taken:

0. iii-title?tgh iitttiiiti'ii j::1:: aboiii $2 Product $3225 this 15EXAIVIPLE IH Thiophene and Octane-1;; 80460 90 Intermediate l60210 2Catalyst preparation (6) Octylthiophene... 210444 23 esidue above 244 9Theecatalyst.Bcomprising.a mixtureof dihye. droxyfluoboric acid andboron trifluoride was u distilled... The distillate was.essentially'pure di- EXAMPLE VI l -y flQ i -aeid (catalyst C). iAbout-one mole of thiophene (about 84. parts 1 H by weight), about 42parts by weight of propylene 1 W and about 80' parts by weight ofcatalyst D were maths cam-Se of aboutjone t 27 parts .25 stirred.forab0ut...2 hours at about 100 degrees by'ivei'ght rOf isobutylene(abolitOAB mole) were Centigrade. e p odu w s s parated f m t gr t -lb wt of thiophene the catalyst, water-washed and distilled. in a (ab'out0.5 mole) and about0;025: part by;weight m fied VigreauX flask. ThefolloW W of thenabove catalyst C; During'ther-additiom of k thealkyiating agent themixture was stirredand 0 maintainedat about40to-ab0ut 45' degreescenti- P d Boiling s G Partsby grade. The:producttwasa separated from:- the m Range Weight catalyst, water-washedand distilledin a modi fied -Vigreaux flask; ,The -fol1owing cutswere- Itaken: 35 ghiopflelnenfi 44 ropy 10p one. 8 di-propylthiophene 5 Residueabove 210 Product- 3 3325.. ggg gg Sp. Gr.

' EXAMPLE 2%; 21 40 Preparation of catalyst (E) fitttlltittttti aii'ii?i2. 813?; Catalyst-E wesrrepared by ma r fluoride to about parts byweight of Water in apressure-resistant container until the pressureEXAMPLE IV 15 remained constant at about 10 pounds per square T0168parts by weight of thiophene (2 moles) Inch u The excess r Pnfluorldewas and. about parts by weight of distilled .dlhy- Vented and about 183welght Oflcatalyst hr'oxyfiuoboricacid (0.48 mole) (catalyst C) wererecPvered havmg, water Q- tnfiuomde mole added during about 30minutesabout 90 parts by y who not exceedmg about to abQut weight ofisobutylene (1.6 moles)! while the "1 Z l fnixture was stirred in anautoclave at about '30 A M anon degrees centigrade. Thereaction mixturewas About one mole (about 84'parts by weight) of stirred for aboutanother thirty minutes and 244: 'thiophene, about one mole (about 112parts by parts by weight of the product (Sp. Gr. (6'0 weight) octene-land about'80 parts by'weight F.)= 0.9646) were separated frornfthecatalyst, of catalyst E were stirred at about 75 degrees water-washed,dried over calcium chloride and Centigrade for about 2 hours. Theproduct -was distilled'irian A. S. TIM. distillation apparatus.separated from "the catalyst, water-washed and 1 Y I distilled in amodified Vigreauxflask; Three B H 1 fractionswere obtained:

as: has v a I. p I 0 Product ifgggg Sp. Gr. l Thiophene and ButylenePolymers -140 40 tbutylthiophene -180 V 40 v 0C q T -250 20 5 Thiopheneand Octene-1 (So-200 V 7 Octylthi'ophena; 200-240 0. 916 43 Edi-octylthiophene andResidue above 240 0.937 87 Catalyst preparation (D)EXAMPLE VIII The catalyst D was prepared by'adding boron 70 About onemole (about 84 par-ts by weight) of uentedui thiophene and-about onemole (about 224-parts by;-;weight)- of hexadecene1 were stirred inapressure resistingcontainer. at about '75 degreescentigradefor about2-hours. During the-first 3,0 minutesonso aboutQO par-ts by weight ofcat r;

were by weight) aboutone mole (about 112' parts by" The prod-.

alyst Ii were added. The product was separated from the catalystwater-Washed and distilld under vacuum.

atal yst F was preparedby adding about 43 parts by weight of catalyst Eto about 2'7 parts by weight of water.

Alkylatz'on One mole (about 84 parts by weight) of thiophene, one mole(about 56 parts-by weight) of isobutylene and about 80 parts by weightof catalyst F were stirred for about 2 hours at about 65 degreescentigrade. The reaction product was separated from the catalyst,water-washed and distilled in a modified Vigreaux flask. The followingfractions were recovered:

Boiling Parts by Product Range Sp. Gr. weight C. Thiophene and OlefinPo1ymer 80-130 0. 928 33 t-butylthiophene 130-190 0. 921 42di-t-butylthiophene 190-226 0. 917 22 'EXANIPLE X Preparation ofcatalyst (G) Catalyst G was prepared by adding about 28.6 parts byweight of catalyst E to about 30 parts by weight of water. 7

Alkylation One mole (about 85 parts by weight) of thiophene, one mole(about 56 parts by weight) of isobutylene and about 80 parts by weightof catalyst G were stirred for about 2 hours at about 72 degreescentigrade. I

The reaction product was separated from the catalyst, water-washed anddistilled in a modifled Vigreaux flask. The following. distillates wererecovered:

Boiling Parts by Product Range 8p. Gr. weight c Thiophene 80-160 0. 96830 t-butylthiophene. 160-175 0. 911 7 Butylene Polymer 175-190 6 Residueabove 190 1 EXAMPLE XI Preparation of catalyst (H) Catalyst H wasprepared by adding about 6 moles (about 120 parts by weight) of hydrogen7 fluoride to about 2 moles (about 124 parts by weight) of boric acidand an equal volume (about 130 parts by weight) of petroleum ether(boiling range 30 to 60 C.) and stirred at about 20 degrees centigradefor about 30 minutes.

Allcylation One mole (about 84 parts by weight) of thiophene, about 0.86mole (about 60 parts by weight) of pentene-l and about 80 parts byweight of catalyst H were stirred for about 3 hours at about 100 degreescentigrade in an autoclave at autogenous pressure. The reaction productwas separated from thecatalyst, water-washed and dis tilled in amodified VigreauX'flask to obtain three fractions;

Parts by Product Range Sp. Gr. Weight 0. Thiophene and Pentene-l- 40-14063 Amyl thiophene 140-195 0. 942 21 Residue. above 195 5 EXAIVIPLE XIIAbout one mole (about 84 parts by weight) of thiophene, about one mole(about 56 parts by weight) of isobutylene and about 80 parts by weightof catalyst H were stirred in a pressure resistant container'forabout 3hours at about 100 degrees centigradeat autogenous pressure. Thereaction product and catalyst were separated, the reaction productwater-washed, the washed product distilled in a modified Vigreaux flaskand three fractions obtained:

- Boiling Parts by Product Range Sp. Gr. Weight 0. Thiopheue 80-130 50t-butylthiophene and Butylene Polymer 130-180 0. 889 44dl-t-butylthiophene 180-220 0. 913 8 EXAMPLE XIII Preparation ofcatalyst (J) Catalyst J was prepared by adding boron trifluoride toabout 30 parts by weight of aqueous fluoboric acid (42 per cent) in apressure resistant container until the pressure remained substantiallyconstant at about 10 pounds per square inch. The excess borontrifluoride (BF3) was vented.

Alkylation About one mole (about 84 parts by weight) of thiophene, about1 mole (about 112 parts by weight) of octene-l and about parts by weightof catalyst J were stirred for about 2 hours at 76 degrees centigrade.The product and catalyst were separated and the product washed withwater. The water-washed product was fractionated in' a modified Vigreauxflask into two fractions.

Boiling Parts by Product Range 7 Sp. Gr. Weight 1 O c. Thiophene andOctene-l 70-140 0. 790 118 Octylthiophene 200-248 0. 911 31 EXAMPLE XIVAbout 56 parts by weight (one mole) of isobutylene were added to about42 parts by weight (0.5 mole) of thiophene and about 10 parts by weightof 42 per cent commercial aqueous fluoboric. acid (catalyst K). Themixture was stirred for about 2 hours at about degree centigrade. Theprodzacetate 11" not was separated from withwater and distilled.

the catalyst, washed 12 ten-washed 'pt f uet fw'as distil-ledi'nained'ified Vigreauxflask" into twofrac'tio'ns.

Product iggg SD: GT-

Product $2325 Sp. Gr. vfi igl DC C- Thiophene 70-90 19 Thiophene andt-butyl alc0hoL 50-130 91 Biityle'ne POIYIDBL 90-160 20 t-butylthiophene130-170 0. 911 3 t-butylthiophene I160-170 0.922- 19 Residue above 170 9Although the present invention has been illus- XQMP trated by numerousexamples, those skilled in E LE Xv the art will realizethat thevariables time of re- Preparation f catalyst (L) action, pressure ofreactionand;temperature of Boron trjfluoride was dd t an aqueousreaction can be varied. Howeven'in general, as Summon about 155 pairtsby weight of HBO-3 thetemperatureo'fjthe reaction is i'ncreas'ed fthe(about 0.25 mole) and about 13.5 parts by weight reaction pressureincreases m I (about 0175 mole) of water in a pressure resistactiondecreases- 011 the other b31111; bbflibwhttt ant container tosaturation, i. e., until the presgreater y s of desirable pmducts can besure became constant at-lopounds per square tained when weak'catalystsand relatively ininch. The excess boron trifluoride was vented. itctivealkylating agents are mp y yn r s- The constituents of catalyst Ltherefore had been 8 the e c temperature Without materially reacted inthe mole proportion BFslI-IBOsIHzO reducing the reaction tlmeof 4:1:3. 7Furthermore, while-the novel process has been A'ZKyZatZ-On illustratedhereinbefore generally by examples v of the treatment of thiophene, thepresent proc- About 3 Parts y Weight (about 1 mole) of ess may beused-for the alkylation of thiophene t p about 55 Parts by weig t (about1 derivatives having at least one replaceable-nu mole) of is y a d a ut80 pa t by clear hydrogen atom. In addition, it is to be un- We ofCatalyst Stirred ar 3 derstood that olefins having 3 to 26 carbon atomsresistant container at 'QZ pressure at are the preferred alkylatingagents although oleabout 75 degrees centigrade for about 2 hours. mhaving 2 carbon atoms may l b d, The reaction mixture was separated fromthe We a catalyst, washed with water and distilled in a 1, A m thod ofalkylating thiopheneand thio'; modified V rea fl Three fmbtidfisWeIT'ephene derivatives having replaceable'nucleafhycovered. drogenwhich comprises reacting a 'thiophene from the class consisting ofthiophene and thio- Boiling Pamby phene derivatives having areplaceablehydrogen Pmduct i Range Weight attached to the thiophene nucleus withalkylating '40 agents under-alkylatingconditions in the presc. ence of acatalyst consisting of dihydroxyfiuo- Thiophelie 60440 8 boric acid. g?Ei,YJ$ 3EtZHQ-" 328 819153 18 2. 'A method of alkylatingthio'pherie andthio- Residue above 250? 3 phene derivatives having a replaceablenuclear 1 5 hydrogen which comprises reacting a thiophene EXAMPLE XVI Ifrom the class consisting of thiophene and tl iophene derivatives havinga replaceable'hydrogen About 42 p s by weight (about 0.51110thioattached to the thioph'enenucleus with"a1kylat+ phene, about 45parts by weight (about 0.49 mole) ing agents under alkylating' d t n inine of tutyl hl ride a d about 16 parts y Weight presence ofdihydrbxyfiuoboricacid' altleastpan of ndi d c y t -Hs 2 2+ 3 weretially saturated with boron'trifluoride. stirred at about 60 degreescentigrade forabout 3; 53 5 f y gt h 'm jhn h t n half houry r0eenchloride was evolved.) phene derivatives-having a replaeeableniiclearThe reaction productwas'separated from thecathydrogen which-comprisesreacting athioplie'iie lyst d water-Washed- The water-washed 55 from theclass consisting of thiophene'and thio product was fractionated in'a:modifiedvigre'au'x phene d i ti having replaceablehydrogen fl intotbree'distillatesattached to the thiophene nucleus withalkylating'agents under alkylating conditions in the V presence ofdihydroxyfluoboric'acidatdeastpar- Product @51 2? vg iz tially saturatedwithhydrogen fluoride.

' 4. A method of alkylating thiophenei'andthiof- 0. phene derivativeshaving areplacea'bl'emuclear Ettiifii? 5tt;e i figg 0. 940 g m m f mb ie di tin he qfi Residue above 180 e from the class consisting ofthiophene and thio- Y '65 phene derivatives having replaceable hydrogenI attached to the thiopheriefiubleus with olefins EXAMPLE XVII having 3to 26, carbon, atoms undersalkylating About 42 parts by weight (about0.5 mole) of conditionsin thepresence of acatalystconsisting thiopheneand about' ldpa'rts by Weight (about of' di hydro yfluoboricacid. j 0.61mole) t-butyl alcohol were a'dded slowly'at 5. A method of alky i ph 'neand-T1 65 degrees Centigrade to about l6parts by'weight phenederivatives having a replaceable nuclear of undistilled catalystB(HsBOzFz-i-BF3). The hydrogen which comprises reacting a thiophenereaction was allowed to proceed for about two from the classconsi'stin'g of thiophene and-thiehours. The reaction product wasseparated from phene derivatives. havinga replaceable hydrogen thecatalyst and washed with water. The w'aattachedetoflthesthiophenenucleus with-.olefins 13 having 3 to 26 carbon atoms underalkylating conditions in the presence of dihydroxyfluoboric acid atleast partially saturated with boron trifluoride.

6. A method of alkylating thiophene and thiophene derivatives having areplaceable nuclear hydrogen which comprises reacting a thiophene fromthe class consisting of thiophene and thiophene derivatives having areplaceable hydrogen attached to the thiophene nucleus with mercaptansunder alkylating conditions in the presence of dihydroxyfluoboric acidat least partially saturated with boron trifluoride.

7. The method of alkylating alkylatable thiophene which comprisesforming a reaction mass containing an alkylatable thiophene having atleast one replaceable hydrogen atom attached to the thiophene nucleus,an alkylating agent and a catalyst consisting essentially ofboron-fluorine acids containing not more than 54% fluorine, up to 17%boron and at least 2.8% hydrogen and having a fluorine to oxygen ratioof about 0.65 to about 17-8 to 1, and holding said reaction mass atabout 10 to about 200 C. for about 0.25 hour to about 3 hours, the lowerthe fluorine to oxygen ratio the higher the reaction temperature and thelonger the reaction time.

'8. The method of alkylating alkylatable thiophene which comprisesforming a reaction mixture containing an alkylatable thiophene having areplaceable hydrogen atom attached to the thiophene nucleus, analkylating agent selected from the group consisting of iso-oleflnshaving .3 to 26 carbonatoms in the molecule and normal olefins having 5to 8 carbon atoms in the molecule, and a catalyst consisting essentiallyof boron-fluorine acids containing about 34 to 44% fluorine, about 5 toabout 8% boron, about 5 to about 7 hydrogen and having a fluorine tooxygen ratio of about 0.65 to about 1 to 1, and holding said reactionmass at about 65 to about 200 C. for about 2 to about 3 hours, the lowerthe fluorine to oxygen ratio the higher the reaction temperature and thelonger the reaction time,

9. The method of alkylating thiophene which comprises forming a reactionmass containing an alkylatable thiophene having at least one replaceablehydrogen atom attached to the thiophene nucleus, an alkylating agent anda catalyst consisting essentially of a boron-fluorine acid containingabout 45.3% fluorine, about 12.9% boron, about 3.6% hydrogen and about38.2% oxygen, and holding said reaction mass at about 10 to about 200 C.for about 0.25 to about 3 hours.

10. The method of alkylating alkylatable thiophene which comprisesforming a reaction mass containing an alkylatable thiophene having atleast one replaceable hydrogen attached to the thiophene nucleus, analkylating agent and a catalyst consisting essentially of boron-fluorineacids containing about 29 to about 47% fluorine, about 38 to about 72%oxygen, about 5 to about 17% boron, about 3 to about 7% hydrogen andhaving a fluorine to oxygen ratio of about 0.51 to about 12:1, andholding said reaction mass at about to about 200 C. for about 2 to about3 hours, the lower the fluorine to oxygen ratio the higher the reactiontemperature and the longer the reaction time.

PHILIP D. CAESAR. GEORGE C. JOHNSON. JOHN W. BROOKS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,141,611 Malishev Dec. 27, 19382,376,119 Bruner May 15, 1945 2,396,144 Anderson Mar. 5, 1946 2,429,575Appleby Oct. 21, 1947 2,432,482 Matuszak Dec. 9, 1947 OTHER REFERENCESRichter, Organic Chemistry, pp. 649-650, Wiley, N. Y., 1938.

Bernthsen and Sudborough, Organic Chemistry, page 549, Van Nostrand, N.Y., 1922 edition.

Caesar and Sachanen, Ind. Eng. Chem. 40, 922, (1948).

1. A METHOD OF ALKYLATING THIOPHENE AND THIOPHENE DERIVATIVES HAVINGREPLACEABLE NUCLEAR HYDROGEN WHICH COMPRISES REACTING A THIOPHENE FROMTHE CLASS CONSISTING OF THIOPHENE AND THIOPHENE DERIVATIVES HAVING AREPLACEABLE HYDROGEN ATTACHED TO THE THIOPHENE NUCLEUS WITH ALKYLATINGAGENTS UNDER ALKYLATING CONDITIONS IN THE PRESSENCE OF A CATALYSTCONSISTING OF DIHYDROXYFLUOBORIC ACID.